The IEEE 802.11 standard defines two operating modes for supporting wireless local area networks (WLANs)—an ad hoc mode and an infrastructure mode. In the ad hoc mode, two or more stations (STAs) can recognize each other and establish a peer-to-peer communication without the need of an access point (AP). In the infrastructure mode, there is at least one AP that connects to one or more STAs. The AP and its associated STAs are known as a Basic Service Set (BSS). A STA may use the AP to access resources on a wired network, such as an Internet, local area network (LAN), or intranet. The STA may also use the AP to communicate with other STAs in the same BSS.
New WLAN devices introduce a complex and important feature called multi-role multi-channel. This feature enables a single WLAN device to act as multiple WLAN devices, even on different channels or frequency bands. When the device leaves one channel or band, such as to perform a different role, the original role might suffer from phenomena that are not treated in the 802.11 standard. For example, in one role, a multi-role multi-channel device may act as an AP on a first channel and, in a second role, act as an AP on a second channel or act as a STA on the same or a different channel. When the multi-role multi-channel device leaves an AP role, any STA that attempts to connect to that AP role will not be able to discover it and connect. As a result, the AP absence may cause very long unconnected periods while the STA waits until the multi-role multi-channel device returns to the AP role, if it resumes the AP role at all.